Process of treating gilsonite



Patented Feb. 16, 1926.

UNITED-STATE 5 PATENT OFFICEQ CHARLES N. FORREST, OF RAHWAY, NEW JERSEY, ASSIGNOR TO THE IRARBER AS- PHAL'I. COMPANY, OF PHILADELPHIA, VIRGINIA.

Application file d August 1 To all whom it may concern.-

Be it known that 1, CHARLES N. FORREST, a citizen of the United States, and a resident of Rahway, in the county of Union and State of New Jersey, have invented certain new and useful Improvements in Processes of Treating Gilsonite, whereof the following is a specification. Y

My invention relates to gilsonite products iid their manufacture, and its object is the ap-reduction from gilsonite of various fiseful substances in a commercially practicable and economical way. The novelty of my invention resides not only in my processes and methods of manufacture, but extends, also, to some of the substances obtained, which are in themselves new.

My present application, it will be understood, is in part a continuation of my application, Serial No. 195,721. filed October 10, 1917, under the title Liquid hydrocarbon.

Gilsonite is a natural solid bitumen, of well known physical properties, including a peculiar, characteristic co nchoidal fracture, found principally in certain sections of Utah. As compared with other natural bituniens in their native state, it is remarkable for its very high degree of purity. Its specific gravity at 7 7 F. varies over a range of, approximately, 1.040 to 1.056. It has been used as an ingredient in paints and varnishes; in paving, waterproofing, and

roofing 'compo-unds;-' and in rubber manufactures.

Of the chemical nature or possibilities of ilsonite, practically nothing is a known. Scientific investigations heretofore attempted have been perfunctory, abortive, and inconclusive; and exploitation commercially has not even been attempted.

The vague state of the worlds informas I I 1 3 tion regarding gilsonite prior to my invention is well illustrated in a paper by Day entitled Investigation of Utah gilsonite, a variety of asphalt read June 18, 1895, before the chemical se tion of the Franklin Institute (Journal 0 the Franklin Institute, Vol. 140, pp. Ql23,7, September, 1895). Vhilc PENNSYLVANIA, A CORPORATION OF WEST PROCESS OF TREATING GILSONITE.

9,1919; Serial No. 318,588.

others are such as naturally to discourage all expectation of useful products from gilsonite.

Days work avowedly failed of attainingthe definite information that he sought regarding the nature of gilsonite; and his owntentative conclusions go very little further than that distillation of gilsonite is unpromising, and that future work on the substance should be along the lines of direct treatment with reagents such as nitric and sulphuric acids, according to a method outlined as a result of his investigation. While the indefiniteness of hisdescriptions makes any attempt to repeat or reproduce his work quite futile, such data and results as he does report, nevertheless, show very clearly that he could not really have been working with true gilsonite at all,-except,- perhaps, in admixture with dominant amounts of other substances. Thus he states that the material on which he worked was lighter than water, whereas in fact gilsonite is heavier; that when heated, his material gave a final, irreducible residue of some 43%, whereas gilsonite yields no more than 30% of residue that all the volatile matter driven 011' by distillation was condensable by water cooling, whereas gilsonite yields such substantial proportions as some 15% ofvapor not'so condensable, including some 13% of well known gases; that no solid separated out in any of his redistillations, whereas, under the gen and nitrogen together, whereas gilsomte contains .-about -2 to 3%-of n1trogen I alone; and that his refining operations consumed a proportion of. the oil treated that is almost unbelievable. It is also noteworthy that he does not mention the peculiar con- 'sonite.

sawdust and fresh herring,

' Day tells of making,

choidal fracture so eharacteristic of gil In a, later paper (Am: Philosophical So ciety, Proc.,'Yp; :37, pp. 171-474; 1898), by distillation of pine a substance which he found practically indistinguish able from native gilsonite.

I have discovercdthat, by suitable treat ment, giving rise .to phenomena and results quite different from any thing indicated by Day, and itself also very different in many respects,

of the invention will be indicated-in my claims. v

The figure is a flow sheet beginning with crude gilsonite. It shows the steps of the process and their relation" to each other-With the products derived from the process.

Nhil'e physically homogeneous and of relatively. simple composition, chemically gilsoriite is highly complex". Not onlydoes chemical analysis show thatit contains a number of diiierent elements, but there are many 1ndications that its characteristic molecule, (or moleculesyuare'of very high molecular Weight and of corresponding structural complexity. According to my invention, 1 break up or decompose this complex material n sucha Way that there may e obtained and segregated or collected separately a number of diiierent products and classes of products. Of these, part have the character of permanent gases or vapors uncondensable at ordinary temperatures; part are vapors condensableas liquid, mostly oil; and part in the form of solid coke. The gaseous portion is of such a character to i be at once serviceable as fuel or as an illuminant;,but it is of considerable complexity, and can be made to yield nitrogenous and other useful products without iu'ipairment of its combustivc utilityf The coke is not only susceptible of d' "cct use as-iuel, or 0% conversion into fuel gas (of somewhat dif ferent character from that obtained as above), but has a nitrogenous content that can readily be released and segregated in useful form as an incident to conversion oftlie coke into fuel gas, if the antecedent operation has been appropriately conducted.

The liquid products preseutthe utmost.

to speak. directly products, and ,that- Lisvaree variety and complexity, and have, moreover,

- a nitrogenous content very readily. segregated in useful form. Though the mixture or aggregate of them resulting from the decomposition is, indeed, at once directly utilizable, their specific properties are so diverse that they can generally be utilized to the best advantage when more or less scpa a ted from ,one.anolher,'-or, at least, divided up into relatively homogeneous lots ordractions, so These fractions may then be used or further treated to bring them into-a more useful state; or made the basis or raw material for the preparation of other valuable products.

, "In-its more complete or integrated form (designed to recover or utilize the entire substance of gilsonite as fully and advantageously as may be), my process involves a firstmain step that is most readily carried 'out by progressive distillation of the gilsonite destructive in character,

together with further or subsidiary main steps that maybe carried out bycombustion of the coke from the initial distillation, and by redistillation of the primary crude oil distillate (repeated :1. number of times'in'some cases) in the natureof fractionation or reduction. Preferably, of course,'the vapors from all distillations Will be appropriately chilled OIKOthGI'WlSQ treated to segregate and recover various different useful components separately. From the description of my preferred mode of procedure, however, it will become apparent that various benefits and l advantages of my invention can be realized even when one or more of the above-indicated steps is omitted,an'd even, indeed, when the vapor from the initial distillation of gilsonite is not collected or condensed. 1 It may be noted as a point in the economy of my complete process that burning of the fuel products obtained as described above (the two lots or kinds of fuel gas, in particular) affords all the heat necessary for 1 carrying out its two main steps of distillation, so that the process is thus thermally balanced or self sustaining. Another important point is that the unconsumed portion of the reagents required or advantage- 1 ously used in the treatment of the fractionated liquid products can be utilized completely and very advantageously in the segregation of the various lots or portions of nitrogenous pi'oduct s'above mentioned.

The procedure which I prefer to employ is as follows:

Gilsonitc as rcceivedffrom the mine is charged into an iron or steel still, fired with gas or oil (or otherwisesuitably heated), 1 and connected to a suitable coiuleuscr,-such as an iron pipe condenser water-cooled. Any convenient quantity of grilsoniie may be Cli&1,18(l,$t f coo pounds to several tons. The-still being closed and heat applied 1 neath it;

gradually, the gilsonite will liquefy and collect in the bottom of the still, and vapor and gas evolving from it will fill the top of the still and pass over into the condenser. As the heating progresses, temperature readings should betaken from time to time on the body of vapor in the upper portion of the still, as well as on the body of liquid be- (Excepting as there may be special occasion for'distinguishing them, I here and hereinafter comprehend mingled gases and vapors under the, sin le term vapor, for the sake of brevity. atherwise, I have applied these terms in accordance with fami iar popular usage, having reference to the usual state of substances at ordinary emperatures. For convenience, I refer to =.rious stages of operations by the corresponding vapor temperatures, unless otherwise specially noted.) The efiect of the progressive heating of the gilsonite is to gradually break .it up and decompose it chemically, as above mentioned,whence, mainly, the evolution of'vapor. It is a difficult matter to. describe the process, or to determine in what order various products are formed or come off, since the coming off of particular products depends on the stability under. heat of the highly complex.

chemical combinations amongst the constitucuts of gilsonite, as well as upon the boiling pointsof the products themselves. The

matter is further complicated, nodoubt, by the liberation, formation, and decomposition of intermediate products, both in the body of liquid andin the body of vapor.

However, the coming off of vapor from the still begins at a temperature of some 165 "F -and continues up to or even beyond cok- 40 ing temperatures. As hereinafter indicated,

' 1 there is a yield of some 15% of vapor not conde'nsable by ordinary water-cooling, including some 13% of gases. The yield of oil vapor includes a minor amount of heavy oil vapor that is condensable at relatively high temperatures,-and is thick and gummy at ordinary temperatures, appropriate for condensing the bulk of the total amount of oil" vapor. It is ofinterest to note that the i'distillation gashas a' greater proportionate nitrogenous content than that from any hydrocarbonaceous material.

Up to the point where the vapor temperature approaches some 550 F.,' the distillation-may be carried out. as rapidly as the contents of the still can be made to absorb heat. 2 At this point; however, some exothermic or other peculiar action occurs, so that the evolution of vapor in the still tends to become excessively rapid. Unless, therefore,

' the-previous heating has been especially slow, it is necessary to reduce the applicatiom-otl. heat very greatly as this critical point-is approached, in order that the then undistilledliquid residue may not spew out of the still, so to speak, and thus be carried over into the condenser, and clog it up so as to render it unusable. In practice, it will usually be found convenient to cut down the iire some 100.F. in advance of this temperature. Once this critical point is well passed, the fire may be increased and the distillation pushed on as rapidly as desired to its conclusion.

Care should be taken that the solid co? product in the still shall not reach a higher temperature than 1000 F., which is just may all be led into the iron pipe condenser,.

as above suggested, and all 0 the strictly vaporous portion thereof there condensed and collected as a li uid, a-slightlydifierent procedure-is preferzilile. As already stated, a minor portion of the. vapor is condensablc at relatively high temperatures and at the tempeartnrles in the condenser appropriate for condensing other portions,-the corresponding condensate is of such thick, gummy consistency that it would tend to clog it up. It is desirable, therefore, that this heavier portion of the normally liquid products be preliminarily" condensed and colected scpmitcly, without entering the condenser. at all. This can advantageously be taken care of by making-the pipe leading from the still to the condenser of substantial length and providing it with a trap. With this arrangement, this troublesome minor portion of the distillation products will be condensed by the cooling effect of the atmosphere ,upon the pipe which thusacts as a sort of auxiliary condenser), and will collect in the trap, whence it can be drawn oil from time to time and added to the liquid products drawn from the condenser itself. In other words, the distillation vapor is first chilled preliminarily iu'the auxiliary condenser to condense and separate out this heavier, higher boiling portion, and then further chilled in the main condenser to condense other portions- The trap also at- ,fords ameasure of protection against the spewing efl ects of too-rapid heating at the critical temperature above mentioned.

Thetruly gaseous portion of the distillation products will pass uncondensed throu h the condenser and be collected separate y.

" t on, the hydrocarbon .ation with a light oil (such as spindle oil) and subsequent distillation o't'this oil. it

this oil-scrubbing is resorted to, it should preferably be done prior to theltvater or sulphuric acid scrubbing. I I

Taking representative percentages, the products into which .thc-gilsoniteis converted by the first stepof my process are about as follows:

Light hydrocarbon oil -c 2 Ammonia (NI-I .c.- Hydrocarbon t'ucl gasuq n 12.75 Distillate c; v Coke In the absence of the oilrscrubbiugSbpcrw fuel gas from the firimary distillation is a mixture with an average"heathe value ot-as high ,as 930 B. t. u, per cubic toot. It contains methane and other hydrocarbons sojthat' it-can be. burned with a luminous flame or used toenr rich and render lur'ninousether fuel'ga's.

llccause of its hydrocarbon content, itjniay conveniently be dlstmgu shedas hydroi a i rig to some 5 or 6%, which is about 1 1,, a men (a means oi ammonium sulphate! Practically all; of the coke is used up in the gas producer treat, ment,'the ash amounting to but a triflingfl t'o-filfki I i I I The significance of the abovementioned upper temperature limit of 1000" for the cd from albhuric acid scrubbing OPCl.ll'-,

Ell

coke (luring distillation and its coincidence with the initial combustion or kindling tern perature of the latter may now be readily understood, by considering that in orderto release nitrogenous iroduct's in the gas produccr, it' is natural y necessary to ear ass "the limitof the (llSiZlllEttlOElfivi-lllllllg w ich the nitrogen amenable to all teu'iperatnrcs "then attained was driven oil in the distillation vapor. Such nitrogen-as fails to come off at the lower tempcraturesattah producer combustion I continues, i. I underthe "higher temperatures there sub sequent-ly attainecl, and eventually comes oil only in forms (other than anunouia) in which is not usefully recoverable. It will carbon fuel lts average percentage. also be seen that the lower the final or maxicomposition is about as follows: mum temperature of the coke in the distilla- Y 7 tion the greater its oossible nitro en corias i a; f -11., Illumirlant hydrocarbon (5.6 6 0 m The hydrocarbon oil distillate extracted from the gas by the oil-scrubbing operation is a very light, colorless, volatile liquid, vaporizing rapidly at ordinary temperature,- and boiling from 80 F. to 200 F. It, is suitable, in general, for the same purposes as similarly low-boiling hydrocarbons now on the inarket,-such as conversion into illaminating gas in small isolated plants.

'lhe nitrogen-bcaring coke that collects in the bottom of the still can be broken up and removed at the conclusion of the distillation, after it has cooled sufiiciently. It is of interest to observe that unless this nitrogenous coke has been superheated be vond the tenuaemture range indicated above, its unfixcd nitrogen content is quite substantial, exceeding 1%, and, in fact, amounttcniperature above indicated will be unfixed and releasable for recovery as ammonia. lnjf I other Words, the unfixed'nitrogen content of such gilsonitic colic corresponds to the maximum. temperature to which the coke, s subjected in the distillation.

technique of controlling the distillation with reference to releasability of nitrogen from the coke involves a sharp departure from ordinary practice in the treatment c t-hydrocarbonaceous uiaterial, according to which distillation is pushed to the utmost limit with a view to getting out as'muchanzimonia" and oil, -etc., as possible in the distillation vapors, and the; coke left to take care of itself. I

The remainder It will be apparent, therefore. that my I of the producer gzis, after the scrubbing operation for extract on or cubic foot, and is practically non luminous;

:A. portion of this secondary fuel gas'may be satisfactorily enriched and rendered luminous by mixture therewith of the. primary hydrocarbon fuel. gas.

The average percentage composition of this secondary fuel gas from the coke is about as follows:

CO., ..h

(30; 11 GIL 3.5 H 24 N 46 Illuminant hydrocarbon; .5

The was liquid distillate (i; e., the mixture of the portions drawn oil from the condenser and the tra contains some2 to 5% of water, and in t is water is dissolyed the nitrogenous content of the crude distillate above referred to, in the form of ammonia.

' its fluorescence and becomes dark brown to black, and absolutelyopaque' in sections of any considerable thickness. It has a characteristic pungent odor, difiicult to define, and rather unple ant. It begins to boil at about 140 F. an distills completely below 700 F.; itfiashes in the air at ordinary temperatures. It contains a very high percentage -mineral oils.

high proportions of the 'wax heremigter of unsaturated hydrocarbons,usually about 60%, as Wellas combined nitrogen .in proportions (some 0.2%) that are likewise unprecedentedly high as compared with other It also contains relatively mentioned, amounting to some 1%. immiscible and insoluble in water, but completely soluble in benzole and carbon-b1sul phide, and miscible in all .pro ortions with petroleum and petroleum pro ucts, turpentine, and pine oil. Itpresents' a remarkable combination of parailinic characteristics with asphaltic ones such as hereinafter particularly pointed out with reference-to lubricating oils obtainable from it. It is use 'ful as a flotation reagent'for the treatment of ores by the flotation process, es cially" on account of its favorable ratio,as tween I saturated and unsaturated hydrocarbons.

As already intimated above, this crude oil distillate is a highly complex material, capable oi fractionation to an almost unobtainable from it not only exhibit diverse properties which fit them for a great variety of industrial uses, but are susceptible of chemical treatment,- purification, modification, and conversion to yield a great variety of new and useful substances and materials.-

In ractice, it is most advantageous to initial y separate the crude oil into a. comparatively small numberof fractions, byredistillation in a suitably heated iron or steel still. The redistillates may, if desired, be further purified by treatment, preferably with sulphuric acid and subsequent neutralization of the excess of reagent with, alkali, such as caustic soda in. a ueous solution. The following examples (w erein the tem- .peratures given are the vapor temperatures in the still, unless otherwise stated) .will sufficiently illustrate the most convenient methods of redistillation:

( 1) Condense separately the vapors coming from the still up to 47 5 F. and from 475 F. to 600 F.,-subseq'uently drawing off as residuum the oil unva'porized at the latter temperature, or allowing it to remain and mix with the next charge of crude distillate. Y

(2) Condense separately. the vapors u to 475 F.; from 475 F. to650, F.; and rem 650 F. until the temperature of the material in'the bottomof the still is about'850 F. By-this procedure, an; amount of coke equal to about 2% of the 'cr'ude oil char e will be reduced; it may be treated int e gas-pro ucer along with that from the.primary distillation. The percentages of the products thus obtained are about as follows Light 'oil 24 Medium oil .r r 35 Heavy oil 36. Coke 2.5 Gas, water, etc. 'L'- 3.5

structive action occurs in the roduction of the higher fractions,--especial y the last;

(3) Three; fractions nearly similar .to those described under- (2) ma be obtained at temperatures some lower than those mentioned by carrying out the redistillation as described in U. S. Patent 877,- 620, granted J an. 28, 1908, to-Wells, blowing carbon dioxide on other inert permanent gas through the liquid' in the still. In this case,

the-destructive action is much less. It is In either of these cases, considerable de-."

advantageous to pass the gas andva'por ooming ofl'throu' h a' filter-of fullers, earthin the dormant t e still, on its-way to the con denser. A residuum of heavy-oil willf'prefa" erably be left under 1). Y

The light distillate produced in' any of these ways is a yellow 011 which becomes red in. the still, as described on standing. Aftersulphuric acid urifica-- limited extent. The different products thus .tion, it may be desirable to redistl 1 it re- &

ductively. in order to improve its color,- leaving as residuum in the. still the small -portion of the oil not cornin'g off below 425' F. The.'reduccdand resultant purified product is a light". colorless,completely volatile oil; with mild" lcrpene odor-slightly suggestingturpentine; of specific gravity about .74 to/TS; and ofexceptionally'high and=diverse solvent capacity for substances used in the paint and varnish industry: specifically, its solvent capacity for varnish gums is substantially greater than that of the most similar petroleum derivatives. its terpene characteristic is considerably more marked than in the case of refined pctroleum, especially after prolonged standing.

' The intermediatedistillate oil is a yellow oil with green fluorescence when fresh; on standing, it becomes first red and then, eventually, a deep reddish brown. Its specific gravity is'about .870) It is capable of use as gas oil or fuel oil Without sulphuric acid purification. .It is'inore reactive to sulphonating reagents than-the most similar mineral oil distillates from petroleum. or

other known hydrocarbonaceous material.

It is susceptibleof'sulphonation treatment with oil of vitriol and oleum (preferably after preliminary purification with a small percentage of oil of'vitriol) to yield various "esenn products.

which after neutralization and redistilla- 'tion' is 'a thin,'c.lear oil, substantiallycolor+ properties; and a. water-soluble product with the useful properties (hydrolyzing, detergent, emulsifying) generally characteristic of true sulphoni'c substances. These last two.

40 products can be segregated by diluting the sulphonation sludge with an equalamount of water and allowing the solution to stand at a temperature of 150 F. and separate into layers by gravity. Of. the resultant Mi-layers, the top comprises the reactionoil and the middle the aforesaid water-soluble sulphonic product, while the bottom co n.- prises most of the unconsurned sulphuric acid diluted with water. The middle layer.

inay be freed from contaminating organic impurity by neutralization, which sets the impurity free to rise tothe surface and be removed,-or, in like manner, by free diluticn with water. l \1 The heavy distillate oil is aysornewhat. viscous reddish-yellow oil with green fluor-. escence when freshly. prepared; on standing, it becomes aliiiost black or brown'in a thin film. Its specific gravity is about "927. Both it and the residual oilrcdistillatetif produced) are suitable for use as flotation reagent Without further treatment. The residual oil has a specific gravity of about .938.

These gilsonite. oil fractionsor redistih;

lates havethe same strikingly high content These include a residual less, odorless, and tasteless; a sulphonation' reaction oil of highly useful semi-drying.

' of commercial petroleum lubricating oils:

.ous purifying and sulphonation treatments of combined nitrogen and of unsaturated hydrocarbons as the crude pllll'llll'y distillate desc ribedahove, and the higher boiling fractions contain the gilscnitic wax referred to. The peculiar combination of parailinic 7 and asphaltic properties is even more marked in the high boilin fractions than in the crude distillate itsel "The-heavy distillate is suitable for the niainlfacture of lubricating oil. For this purpose, it may be purified bytreatmcnt with 3 to 10% of oil of vitriol; neutralized .with caustic soda or other alkali; washed with Water; and then chilled to about 32 F. and filter-pressed. This pressing removes from theoila material which, after r' pressing and filtering through fullers earth,

"beconicsa nierchantable wax, hard and crysboil at temperatures exceeding 45 1 and,

for the most part, above 600 F. They are stable against decomposition into products unsuited to lubrication under even the un favorable, conditions of internal combustion engine cylinder lubrication; and they are inert with respect to ordinary metals, so that 1 they will not injure machine parts. Contrary to-the paratlinic character indicated bythe was obtained fronrtheir mother oil tospealr, they have, it will be observed, the relation of flash point to specific .gravityrgenerally characteristic of asphaltic oils 'lhis will readily be observed by comparing their properties as stated with those v California. .asphaltic. fiensityuuv .91 Flashucuu. 395

Parafiinlc. Gllsonitlc. .87 .9

1 ca ting oils have flash points below those for even lighten. paraliinic oils.

I, The .uncensumed portion of the sulphuric acid or; other such reagent used in the vari- 20 aho vedescribed can he used as a reagent for the segregation of mtrogenous products from theprimary gas, liquidand coke products as above set forth. Sulphonation of the intermediate distillate described alcove will afford enough suchunconsumed acid for this .purpose. I

Having thus described my invention, I

. claim 1.. A process of converting gilsonite into oils, ammoniaaud fuel gas, which comprises heiltm'gz-aiul thereby decomposing andd1stilling the gilsoniteto" dryness, at increasing temperatures below that of nitrogen fixation intlieresulting coke, to yield dry coke retaining nitrogen of the gilsonite unlixe-d and alsoz-vapor comprising segrcgable' fuel gas, ammonia, and oil vapor, the latter including 'portions one of which is condcnsable at highertemperature-s than the other and is thickand gummy at 1em w-raturcs as,

' \v hichsueh other condenses; reducing-the application of heat for distillation as the "vapor temperature over the then undistillcd residue approaches and passes 55091911; and, withdrawing vapor as formed from the presence of the undistilled residue,a1id chillmg such 'apor preliminarily-tocondense and separ ite out the thick, gummy portion aforesaid, and further to condense the other portion. 5'

2. A process of converting gilsonite into oils, ammonia, and other gas, which comprises heating and thereby decomposing and distilling the gilsonite to dryness, at increasing temperatures below that of nitrogen fixation in the resulting coke, as yield dry coke with nitrogen content releasable as ammonia and also vapor comprising free ammonia, other gas in substantial proportions, and oil vapor; and,.l') urning the aforefsaid' coke and releasing its nitrogen content as ammonia. A process wh ich comprises heating and thereby decomposing and distilling gilsonite to coke, at. 'increaslng temperatures below that of nitrogen fixation in the coke, to

yield coke retaining nitrogen of the gilsonite unfixed and also oil vapor, portions of which 'are condensable at higher temperatures than other portions and are thick and gummy at temeratures at which said latter portions con ense; withdrawing the vapor as formed from the presence' of the nndistilledresidue,

and prehmi'narily condensin' and separating out the thick, gummy por ions aforesaid, and then condensin the other portions.

4. A process whic comprises heating and coking gilsonite within such limits of makilmum temperature as to retain nitrogen of the gilsomte in the coke unfixed, and treating the coke to releasesuch retained nitrogen as ammonia. 5. A process wl I thereby decomposing-and distilling gilsonite to solid coke, at increasing temperatures below that of nitrogen fixation in the coke, and releasing such retained nitrogen as ammonia-through incomplete combustion of the coke at temperatures exceeding the previous limit.

6. A-process of obtaining nitrogenous products from gil'soni-te which com )rises eating and thereby decomposing an cok- 'ch comprises heating and,

"hard, crystalline wax and stable, inert, viscous lubricating oils-of paraflinic character, having asphaltic relations of flash point to specific grav ty.

8. A process which comprises heating and thereby "decomposing and distilling gilsonite at increasing temperatures eventually exceeding 550 F. for-the vapor over the undistilled residue, to yield oil vapor sinclud ing portions one of which is condensable at higher temperatures than the other and is thick and gummy at temperatures at which such other condenses, reducing the application of heat asthe vapor temperature over 1 the residue approaches and passes 550 F.;

and progressively withdrawing the vaporfrom the presence of the undistilled residue, and preliminarily condensing and separating 9. A process which comprises heating and thereby decomposing and distilling gilsonite to yield oil vapor incIudin portions one of which is condensable at hi ier temperatures than the otherandis thic and gummy at temperatures at which such other condenses; and withdrawing the vapor from the res ence of the undistillcd residue, and pre imi narily condensing and-separating out the thick, gummy portion. aforesaid, and then condensing the other portion.

10. A recess which comprises heatin i there y .decomposing and distilling gi sonite at increasin temperatures eventually exceeding materially 550 F. for the vapor over the undistilled residue, materially reducing the application of heat, however, as

such vapor temperature approachesand passes that figure. 1

11. A process which com rises heating and therebv-docom osing an distilling gi son'ite until the an istilled residue; is coked, at increasing temperatures below that of nitrogen fixation in the coke, to yield coke with nitrogen content releasable as ammonia and also vapor comprising segrtgibleoil vapor and gas; reducing the application of heat, however, .a's'the vapor temperature.

but the thick, gummy'portion aforesaid, and then condcnsing the other portion.

over the then undistill'edresidue approaches and passes 550 F..

able as ammonia, and ,ot ,er useful products,

recess: of producing, from' gil sonlte, co 0 with mtro encontent recoverwhich comprises heating and thereby def strnctively distilling the .gilsonite to solid, non-melting coke, at increasing temperm turesbelow that of nitrogen fixation in the coke.

13. A process of obtaining, from gilsonite,

non-melting coke with recoverable nitrogen i content, which comprises hentlngend thereby decomposing and coking the gilsonite at increasing temperatures up to a maximum offfrom 850 F. to 100091 i 14, A process which comprises heating and thereby decomposing and coking gilsonite at increasing temperatures, with a maximum, for the residue, of some 850 F.,

'to yield dry, solid coke-with corresponding unfixed nitrogen content.

15. A process which cou'iprrses heating and thereby decomposing and distilling gil sonite, at increasing temperatures eventually exceeding 550 F. for the vapor over the then undistilled residue, until the residue is coked. l

'16. -A. recess which comprises heating and there y decomposing and distilling gilsonit'e until the undistilled residue is coke'd,

at increasing;' temperatures. eventually exeroding 550" E, but below thntof nitrogen iixulion in the coke.

' 17. A process which comprises heating :uul'thereby decon'iposing and distilling'gilsonite at increasing temperatures yielding oil vapors of varying boiling points up to and including a high-boiling portion that is thick andrgiunmy at temperatures at which the low-boiling portion condenses, and also gas iii substantial proportions.

'18. A process which comprises henting and thereby decomposing and distilling g'i'lsonitc at increasing temperatures eventually sufliciently high to yield distillate comprising hard, crystalline wax of very high'ineltingpointnnd also stable, inert,viscous lul ricnting oils of parafl'inic character and asph'nlli'c relations of flash to specific gravity,

nml'for the most part boiling be1ow"600 F.-, besides 'gas in substantial proportions.

In testimony whereof, I 'lnive' hereunto signed my name at'Philzrdelphia, Pennsylvania,'this' twelfth day of August, 1919.

CHARLES N'. FORREST. 

